Dansyl amide is a

fluorescent dye A fluorophore (or fluorochrome, similarly to a chromophore) is a fluorescent chemical compound that can re-emit light upon light excitation. Fluorophores typically contain several combined aromatic groups, or planar or cyclic molecules with se ...

that forms in a reaction between

dansyl chloride Dansyl chloride or 5-(DimethylAmino)Naphthalene-1-SulfonYL chloride is a reagent that reacts with primary amino groups in both aliphatic and aromatic amines to produce stable blue- or blue-green–fluorescent sulfonamide adducts. It can also be m ...

and ammonia. It is the simplest representative of the class of dansyl derivatized amines, which are widely used in

biochemistry Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology and ...

and

chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...

as fluorescent labels. The dansyl amide moiety is also called a dansyl group, and it can be introduced into

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...

s or other amines in a reaction with

. The dansyl group is highly fluorescent, and it has a very high

Stokes shift __NOTOC__ Stokes shift is the difference (in energy, wavenumber or frequency units) between positions of the band maxima of the absorption and emission spectra (fluorescence and Raman being two examples) of the same electronic transition. It ...

. The excitation maximum (ca 350 nm) is essentially independent on the medium, whereas the emission maximum strongly depends on the solvent and varies from 520 to 550 nm.Makoto Asano, Frangoise M.Winnik, Takashi Yamashita, and Kazuyuki Horief. Fluorescence Studies of Dansyl-Labeled Poly(iV-isopropylacrylamide)Gels and Polymers in Mixed Water/Methanol Solutions. Macromolecules, 1995, 28, 5861—5866.

References

{{reflist Chemical tests Reagents for organic chemistry